Sealed Break-Open Package and Corresponding Method for the Production Thereof

ABSTRACT

A sealed break-open package having: a wrapping sheet, which is folded and welded onto itself so as to define, alone, a closed containing chamber, which is designed to contain a fluid product and has a dispensing through opening, through which the fluid product can flow out of the containing chamber; and a closing system, which engages the dispensing opening in a sealing manner, so as to close the dispensing opening. The closing system having a semi-rigid plastic material sheet, which overlaps the wrapping sheet in the area of the dispensing opening, is firmly and permanently connected to the wrapping sheet, and has a pre-weakened region, which overlaps the dispensing opening and guides, following a folding of the semi-rigid plastic material sheet, a controlled breaking of the semi-rigid plastic material sheet in the area of the pre-weakened region, so as to determine the formation, through the semi-rigid plastic material sheet, of a product outlet opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims priority from Italian patent application no. 102018000008130 filed on 20 Aug. 2018, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a sealed break-open package and to a corresponding production method.

PRIOR ART

Sealed packages containing more or less dense liquid products have been widespread on the market for many years and are produced by folding and sealing a waterproof wrapping sheet typically using the so-called “Form-Fill-Seal” (“FFS”) method.

To open a sealed package you can use scissors to remove (at least) an upper corner of the sealed package; this opening method is simple, fast, and intuitive but, on the other hand, requires that you have scissors at hand (which you generally do not outside the house).

In other words, this opening method is impractical because it requires you to have a cutting tool at hand (typically scissors, but you could also use a knife).

Alternatively, to open a sealed package, the wrapping sheet constituting the sealed package may be partially torn off along a pre-weakened, tearable line or along an upper sealing line; however, this opening method requires some strength and dexterity and, above all, requires having clean and dry hands to be able to grasp the sealed package with sufficient strength and without slipping. In other words, this opening method is impractical because it requires you to have some strength and dexterity in order to be able to tear off the wrapping sheet without accidentally causing the fluid contained in the package to flow out.

To overcome the drawbacks described above, sealed packages have been developed that are equipped with a plastic spout that is mounted on the wrapping sheet, by piercing the wrapping sheet itself, and is equipped with a screw cap (initially connected to the spout through weak connection points that are broken at the first opening). The spout equipped with a screw cap is comfortable, practical, and functional (and, among other things, it enables the sealed package to be reclosed in a sealing manner after the first opening). However, the presence of the spout equipped with a screw cap leads to a significant increase in the cost of the sealed package (both in terms of the increase in the cost of the wrapping sheet to be used and in terms of the increase in cost of the work to be carried out). It also leads to an increase in its environmental impact as it permanently incorporates a plastic material, which is different to all the other materials the wrapping sheet is made of, into the sealed package. In addition, future ecological regulations, which will require that the cap cannot be separated from the sealed package (i.e. that the cap remains in some way attached to the sealed package), will cause significant complication in the production of the sealed package.

The patent application US2012292340A1 represents the closest state of the art and describes a package that contains a quantity of a condiment confined within a single containing chamber and has a fold region wherein the package is folded on itself. On the outside of the folding region there is a dispensing through opening through which the condiment can flow out from the containing chamber, and there is a breakable seal that engages the dispensing opening in a sealing manner to close the dispensing opening itself.

DESCRIPTION OF THE INVENTION

The purpose of the present invention is to provide a sealed break-open package and a corresponding production method, the sealed package of which is easy and intuitive to use and, at the same time, can be produced in a simple and economical manner.

According to the present invention, a sealed break-open package and a corresponding production method are provided, as established in the attached claims.

The claims describe preferred embodiments of the present invention that form an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the appended drawings, which illustrate some non-limiting embodiments thereof, wherein:

FIG. 1 is a perspective view of a sealed break-open package in a closed configuration and produced in accordance with the present invention;

FIG. 2 is a perspective view of the sealed package in FIG. 1 without a closing system;

FIG. 3 is a lateral view of the sealed package in FIG. 1;

FIG. 4 is another perspective view of the sealed package in FIG. 1;

FIG. 5 is an enlarged scale view of part of the sealed package in FIG. 1 in the area of a closing system and in an open configuration;

FIG. 6 is an enlarged scale view of part of the sealed package in FIG. 1 in the area of a closing system and in a closed configuration;

FIG. 7 is a cross section view along the cross section line VII-VII of the sealed package in FIG. 1;

FIGS. 8 and 9 are two cross section views along the cross section line VII-VII of respective alternative embodiments of the sealed package in FIG. 1; and

FIGS. 10 and 11 are two enlarged scale views of part of the sealed package in FIG. 1 in the area of a closing system and according to two different embodiments;

FIGS. 12-16 are five perspective views of five embodiments of a sealed break-open package in a closed configuration and produced in accordance with the present invention; and

FIG. 17 is a schematic, perspective view of a packing machine that produces the sealed package in FIG. 1.

PREFERRED EMBODIMENTS OF THE INVENTION

In FIGS. 1-4, the number 1 refers, as a whole, to sealed break-open package.

The sealed package 1 contains a predetermined quantity of a fluid product inside and is produced by folding and welding a waterproof wrapping sheet 2 made of a flexible plastic material. In other words, the wrapping sheet 2 is made of flexible plastic material and is folded and welded on itself to define a closed containing chamber designed to contain the predetermined quantity of the fluid product.

The sealed package 1 comprises a dispensing opening 3 through which the product contained in the sealed package 1 can flow out of the sealed package 1 itself; in FIG. 1 the dispensing opening 3 is shown with dotted lines as it is not visible while in FIG. 2 the dispensing opening 3 is shown with a continuous line as it is visible. In other words, the dispensing opening 3 is a through-hole that crosses the wrapping sheet 2 (which constitutes the containing chamber of the sealed package 1) from side to side and, thus, places the inside of the sealed package 1 in direct communication with the outside of the sealed package 1. In the embodiment shown in the attached figures, the dispensing opening 3 has a circular shape; according to other embodiments not shown and perfectly equivalent, the dispensing opening 3 has a different shape from the circular one, for example an elliptical shape, a rectangular shape, or a triangular shape.

The sealed package 1 comprises a closing system 4 (i.e. a cap) with a break opening (i.e. one that needs to be broken open) that engages (closes in a sealing manner, seals) the dispensing opening 3 preventing (until the breaking open of the closing system 4) the flowing out of the product contained in the sealed package 1 through the dispensing opening 3; in other words, the closing system 4 engages the dispensing opening 3 in a sealing manner to close the dispensing opening 3 (until the closing system 4 is broken open).

According to what is shown in FIGS. 6 and 7, the closing system 4 comprises a semi-rigid plastic material sheet 5 that has a rectangular shape, overlaps the wrapping sheet 2 (which constitutes the containing chamber of the sealed package 1) in the area of the dispensing opening 3, and is connected in a stable, permanent, and fluid-tight way (typically welded) to the wrapping sheet 2 (which constitutes the containing chamber of the sealed packaging 1).

In the embodiment shown in the attached figures, the semi-rigid plastic material sheet 5 has a rectangular shape with two longer sides parallel and opposite to each other and two shorter sides parallel and opposite and perpendicular to the longer sides; according to other embodiments not shown and perfectly equivalent, the semi-rigid plastic material sheet (5) has a different shape from the rectangular shape, for example, a circular shape, a semi-circular shape, an elliptical shape, a square shape, a triangular shape, a pentagonal shape etc.

The semi-rigid plastic material sheet 5 has a pre-weakened region 6 centrally that overlaps and aligns with the dispensing opening 3; preferably, but not necessarily, the pre-weakened region 6 is arranged at the centre of the dispensing opening 3, i.e. the pre-weakened region 6 coincides with the centre line of the dispensing opening 3.

In use, the pre-weakened region 6 guides a controlled break of the semi-rigid plastic material sheet 5 in order to determine the formation, through the semi-rigid plastic material sheet 5 itself, of an outlet opening for the product contained in the sealed package 1. In other words, in use, to open the closing system 4 (i.e. to open the sealed package 1) a user must grasp the closing system 4 of the sealed package 1 with the fingers of one hand and (typically with the fingers of the same hand) fold the closing system 4 (approximately) 150-180° until the semi-rigid plastic material sheet 5 is broken in the area of the pre-weakened region 6 (as shown in FIG. 5). By breaking the semi-rigid plastic material sheet 5 in the area of the pre-weakened region 6, a flow-out opening is formed in the semi-rigid plastic material sheet 5 through which the product can be made to flow out of the sealed package 1 in a simple and hygienic way.

According to what is illustrated in FIGS. 6 and 7, the pre-weakened region 6 comprises an outer incision 7 that is obtained through an outer surface 8 (that is opposite to the wrapping sheet 2 that constitutes the containing chamber of the sealed package 1 and faces outwards from the sealed package 1) of the semi-rigid plastic material sheet 5. In addition, the pre-weakened region 6 comprises an inner incision 9 that is parallel to and aligned with the outer incision 7 and is obtained through an inner surface 10 (i.e. from the side of the wrapping sheet 2 that constitutes the containing chamber of the sealed package 1 and faces the inside of the sealed package 1) of the semi-rigid plastic material sheet 5 opposite to the outer surface 8. The inner incision 9 is perfectly aligned with (i.e. overlaps) the outer incision 7 and extends only in the area of the outer incision 7 (i.e. the inner incision 9 completely overlaps the outer incision 7). In other words, the inner incision 9 only extends to the area where the outer incision 7 is located; in contrast, the outer incision 7 could extend beyond the inner incision 9, i.e. there may be end parts of the outer incision 7 that extend to areas wherein the inner incision 9 is not present.

According to a possible embodiment shown in FIGS. 15 and 16, the pre-weakened region 6 extends along a straight line and the dispensing opening 3 has a rectangular shape wherein the longer sides are parallel to the pre-weakened region 6 while the shorter sides are perpendicular to the pre-weakened region 6; in this embodiment, the shape and arrangement of the dispensing opening 3 repeat (marry with) the shape and arrangement of the pre-weakened region 6 enabling the area of the dispensing opening 3 to be minimised to the same length as the pre-weakened region 6.

It is important to underline that, from a functional point of view, the semi-rigid plastic material sheet 5 of the closing system 4 can equally overlap (be placed on, connected to) the wrapping sheet 2 on the outer surface of the wrapping sheet 2 (i.e. outside the containing chamber containing the predetermined quantity of the fluid product) or on the inner surface of the wrapping sheet 2 (i.e. inside the containing chamber containing the predetermined quantity of the fluid product). On the other hand, from an aesthetic point of view, it may be preferable to overlap (place, connect) the semi-rigid plastic material sheet 5 of the closing system 4 on the inner surface of the wrapping sheet 2 (i.e. inside the containing chamber containing the predetermined quantity of the fluid product) so that outside the plastic material sheet 5 is practically invisible (it is, in fact, only visible through the dispensing opening 3); consequently, it is sufficient to take care of the aesthetic appearance of the single wrapping sheet 2 the appearance of which is not disturbed by foreign elements.

According to the embodiment shown in FIG. 7, the semi-rigid plastic material sheet 5 consists of a laminate comprising (at least) one supporting layer 11 of plastic material that is arranged externally (i.e. on the opposite side of the sealed package 1 containing the product and in the area of the outer surface 8) and gives strength and rigidity, and a heat-sealable plastic layer 12 that is arranged internally (i.e. on the side of the sealed package 1 containing the product and in the area of the internal surface 10) and enables the semi-rigid plastic material sheet 5 to be welded to the wrapping sheet 2 (which constitutes the containing chamber of the sealed package 1). Between the supporting layer 11 and the heat-sealable layer 12 there is a barrier layer 13 that guarantees effective protection against air, light, and bacteria that could cause the product contained in the sealed package 1 to deteriorate.

As a non-limiting example, the semi-rigid plastic material sheet 5 could be composed of a supporting layer 11 of white polystyrene (PS) with a thickness of 400 microns (±10%), a barrier layer 13 of “Evoh” or of aluminium with a thickness of 10 microns (±10%), and a heat-sealable layer 12 of polyethylene (PE) with a thickness of 45 microns (±10%).

The outer incision 7 is obtained through the outer surface 8 of the semi-rigid plastic material sheet 5, has a “V” shape (but it could also have a different shape), and is produced by locally deforming the semi-rigid plastic material sheet 5; in particular, the outer incision 7 is produced by deforming just the supporting layer 11 of the semi-rigid plastic material sheet 5, or the outer incision 7 involves just the supporting layer 11 of the semi-rigid plastic material sheet 5. The inner incision 9 is obtained through the internal surface 10 of the semi-rigid plastic material sheet 5, has a “V” shape (but it could also have a different shape), and is produced by locally deforming the semi-rigid plastic material sheet 5; in particular, the inner incision 9 is produced by deforming all three supporting 11, heat-sealable 12, and barrier 13 layers of the semi-rigid plastic material sheet 5.

In the non-limiting embodiment shown in FIGS. 7, 8, and 9, the inner incision 9 partially overlaps the outer incision 7, i.e. the tip of the inner incision 9 overlaps the tip (and therefore “enters” the tip) of the outer incision 7; in this partial overlapping of the inner incision 9 and the outer incision 7, the heat-sealable layer 12 and, above all, the barrier layer 13 of the semi-rigid plastic material sheet 5 are pushed (plastically deformed) into the outer incision 7, i.e. they partially penetrate (enter) into the tip of the outer incision 7. In the embodiment shown in FIG. 7, both the heat-sealable layer 12 and the barrier layer 13 of the semi-rigid plastic material sheet 5 partially penetrate (enter) the tip of the outer incision 7, while in the equivalent embodiment shown in FIG. 8, only the barrier layer 13 of the semi-rigid plastic material sheet 5 partially penetrates (enters) the tip of the outer incision 7 (i.e. the heat-sealable layer 12 of the semi-rigid plastic material sheet 5 tears near the tip of the outer incision 7 and does not penetrate the tip of the outer incision 7). In some situations, and as shown in FIG. 9, a certain “buildup” of the barrier layer 13 may also occur in the area of the tip of the inner incision 9 (i.e. in the area of the tip of the outer incision 7).

In other words, between one end of the outer incision 7 and one end of the inner incision 9 there is the barrier layer 13, there may be the heat-sealable layer 12, but there is not the supporting layer 11 (or it is absent). As a result, the supporting layer 11 has an interruption (i.e. is interrupted, is absent) in the area of the end of the outer incision 7 and, consequently, also in the area of the inner incision 9.

It is important to underline that in the area of the inner incision 9 the barrier layer 13 of the semi-rigid plastic material sheet 5 is locally plastically deformed (even in an irregular way), but is not torn, i.e. it maintains its integrity. Thanks to the substantial integrity of the barrier layer 13 of the semi-rigid plastic material sheet 5, including in the area of the inner incision 9 made through the inner surface 10 of the semi-rigid plastic material sheet 5, it is possible to ensure the perfect insulation of the containing chamber of the sealed package 1 that contains the product, which is therefore also designed to contain products that are perishable and/or have a controlled bacterial load, such as food. Obviously, during the breaking open of the sealed single-serve package 1, achieved by folding the closing system 4 (i.e. the semi-rigid plastic material sheet 5) in a “V” in the area of the pre-weakened region 6, it is necessary to break (only in the area of the pre-weakened region 6) all three supporting 11, heat-sealable 12, and barrier 13 layers of the semi-rigid plastic material sheet 5.

According to a possible embodiment, the two incisions 7 and 9 have the same extension, i.e. where there is the outer incision 7 there is also the inner incision 9 and vice versa. According to an alternative and equivalent embodiment, the outer incision 7 has a greater extension than the inner incision 9 (in this case the outer incision also extends outside the inner incision 9), or where there is the inner incision 9 there is also the outer incision 7 but not vice versa. In fact, the outer incision (in the portion overlapping the inner incision 9) and the inner incision 9 serve to generate, when the closing system (i.e. the semi-rigid plastic material sheet 5) is folded in a “V” (as shown in FIG. 5), a controlled breaking of the semi-rigid plastic material sheet 5 to enable the flowing out of the product 5 contained in the sealed package 1. The outer incision 7 (including in any portion not overlapping the inner incision 9) also serves to guide the “V” folding of the closing system 4 (i.e. of the semi-rigid plastic material sheet 5) so that the vertex of the “V” folding of the semi-rigid plastic material sheet 5 coincides with the incisions 7 and 9.

In the embodiment shown in the attached figures, the incisions 7 and 9 are continuous, i.e. without interruptions; according to an alternative and perfectly equivalent embodiment not shown, the incisions 7 and 9 may be discontinuous, i.e. they may have one or more interruptions (in this case we can speak of two discontinuous incisions 7 and 9 or of a series of aligned and spaced incisions 7 and 9).

The inner incision 9 could have a variable depth along its length; this characteristic is preferable (but not strictly necessary) for improving the opening when the closing system 4 (i.e. the semi-rigid plastic material sheet 5) is folded in a “V” (as shown in FIG. 5). In other words, the fact that the inner incision 9 has a variable depth along its length enables a progressive breaking of the semi-rigid plastic material sheet 5 to be obtained when the closing system 4 (or the semi-rigid plastic material sheet 5) is folded in a “V” (as shown in FIG. 5). Similarly, the outer incision 7 may also have a variable depth along its length. In other words, both the incisions 7 and 9 may have a variable depth along their length, only one of the two incisions 7 and 9 may have a variable depth along its length, or both incisions 7 and 9 may have a constant depth along their length.

The incisions 7 and 9 may also be made differently from what is shown in FIGS. 7, 8, and 9; for example, the incisions 7 and 9 may be made as described in patent application WO2008038074A2 or as described in patent application WO2009040629A2.

In the embodiment shown in FIG. 6, the pre-weakened region 6 comprises a single outer incision 7 (and therefore a single corresponding inner incision 9 parallel to and aligned with it) that is oriented longitudinally, i.e. is arranged parallel to the longer (vertical) sides of the semi-rigid plastic material sheet 5. In the embodiment shown in FIG. 1, the pre-weakened region 6 comprises a single outer incision 7 (and therefore a single corresponding inner incision 9 parallel to and aligned with it) that is oriented transversely, i.e. is arranged parallel to the shorter sides of the semi-rigid plastic material sheet 5. In the alternative embodiment shown in FIG. 10, the pre-weakened region 6 comprises two outer incisions 7 (and therefore two corresponding inner incisions 9 parallel to and aligned with them) that intersect centrally forming an “X”. In the additional embodiment shown in FIG. 11, the pre-weakened region 6 comprises four outer incisions 7 (and therefore four corresponding inner incisions 9 parallel to and aligned with them) that intersect centrally at a single point of intersection forming a star. In general, the pre-weakened region 6 comprises a plurality of outer incisions 7 (and therefore a plurality of corresponding inner incisions 9 parallel to and aligned with them) that can intersect variously (i.e. all the outer incisions 7 intersect each other at a single, common point of intersection or the outer incisions 7 intersect each other at several distinct points of intersection).

Obviously, the shape of the sealed package 1 and the position of the dispensing opening 3 (and, consequently, the position of the closing system 4) may differ from that shown in FIGS. 1-4. FIGS. 12-16 show some non-limiting examples of possible shapes of the sealed package 1. For example, in the embodiment shown in FIG. 14, the dispensing opening 3 (and, consequently, the closing system 4) is arranged in the area of an upper wall of the sealed package 1.

In the embodiment shown in FIG. 16, the dispensing opening 3 is arranged across a lateral folding line of the wrapping sheet 2; in this way, the pre-weakened region 6 can be aligned with the lateral folding line of the wrapping sheet 2, making the “V” folding of the closing system 4 (i.e. of the semi-rigid plastic material sheet 5) easier and more intuitive when opening the sealed package 1. In other words, in the embodiment shown in FIG. 16, the dispensing opening 3 is arranged across the edge of the containing chamber wherein the wrapping sheet 2 is folded into a “U”; in this way, the pre-weakened region 6 can be aligned with the edge of the containing chamber making the “V” folding of the closing system 4 (i.e. of the semi-rigid plastic material sheet 5) easier and more intuitive when opening the sealed package 1.

FIG. 17 shows a “Form-Fill-Seal” (“FFS”) type of packing machine 14 that produces the sealed package 1 described above.

The packing machine 14 comprises an unwinding station S1 wherein the wrapping sheet 2 is unwound from a reel 15. The packing machine 14 comprises a winding station S2 wherein the wrapping sheet 2 is folded into a tube around a feeding duct 16 for a product that must be dosed into the sealed packages 1. The packing machine 14 comprises a longitudinal welding station S3 wherein the folding of the wrapping sheet 2 into a tube is stabilized through a heat-sealing process. The packing machine 14 comprises a transverse welding station S4 wherein the sealed packages 1 are closed and separated by the wrapping sheet 2.

The packing machine 14 comprises a piercing device 17 that makes the dispensing openings 3 in the wrapping sheet 2; alternatively, the dispensing openings 3 can be made in the wrapping sheet 2 upstream of the packing machine 14, i.e. before winding the wrapping sheet 2 in the reel 15 and, therefore, before installing the reel 15 in the packing machine 14.

The packing machine 14 comprises an application device 18 that applies the closing systems 4 to the wrapping sheet 2; each system comprises a semi-rigid plastic material sheet 5 that is connected (welded) to the wrapping sheet 2 in the area of the respective dispensing opening 3. In other words, the application device 18 places a semi-rigid plastic material sheet 5 on the wrapping sheet 2 and in the area of a respective dispensing opening 3 and welds the semi-rigid plastic material sheet 5 to the wrapping sheet 2; obviously, the incisions 7 and 9 that constitute the pre-weakened region 6 have been made in the semi-rigid plastic material sheet 5 beforehand.

In the embodiment shown in FIG. 17, the application device 18 is arranged in the winding station S2 wherein the wrapping sheet 2 is folded into a tube; this arrangement ensures that, after the application of the closing systems 4, the wrapping sheet 2 is no longer folded in the area of the closing systems 4 themselves. According to other embodiments not shown, the application device 18 is arranged between the unwinding station S1 and the winding station S2 (obviously always downstream of the piercing device 17 if present); in this case, it is necessary that the conveying system that advances the wrapping sheet 2 downstream of the application device 18 does not subject the wrapping sheet 2 to too high folding angles to avoid breaking the semi-rigid plastic material sheets 5 in the area of the pre-weakened regions 6.

According to another embodiment not shown, the closing systems 4 (comprising the semi-rigid plastic material sheets 5) can be applied to the wrapping sheet 2 upstream of the packing machine 14 (but always after the dispensing openings 3 are made), i.e. before winding the wrapping sheet 2 on the reel 15 and, therefore, before the reel 15 is installed in the packing machine 14; in this case, it is necessary that the conveying system that advances the wrapping sheet 2 does not subject the wrapping sheet 2 to too high folding angles to avoid breaking the semi-rigid plastic material sheets 5 in the area of the pre-weakened regions 6.

In particular, the advancement system of the packing machine 14 conveys, after the application of the closing systems 4, the wrapping sheet 2, making the wrapping sheet 2 pass through the curved segments that subject each semi-rigid plastic material sheet 5 to folding angles that, to be prudent, should be less than 75° and, in any case, less than 90°-100° at the most.

For example, the incisions 7 and 9 can be made on the semi-rigid plastic material sheet 5 through the incision units described in the patent application EP2944579A2 or in the patent application IT102017000002424.

The embodiments described herein may be combined with each other without departing from the scope of protection of the present invention.

Numerous advantages are achieved with the sealed package 1 described above.

First, the sealed package 1 described above has a simple, intuitive, and very effective opening.

In addition, with the sealed package 1 described above, the closing system 4 is always attached to the sealed package 1 itself, i.e. it is not possible (except by destroying the sealed package 1) to separate the closing system 4 from the sealed package 1.

The sealed package 1 described above is extremely easy and economical to produce, as it simply requires the addition of the closing system 4—consisting of a small semi-rigid plastic material sheet 5 equipped with the pre-weakened region 6—to a standard sealed package 1. If the application of the closing system 4 to the wrapping sheet 2 takes place in the paper mill that produces the wrapping sheet 2, the packing machine 14 that processes the wrapping sheet 2 to produce the sealed package 1 is basically of the standard type.

Finally, the sealed package 1 described above is environmentally friendly, as the closing system 4 is never separated from the remaining part of the sealed package 1 and, above all, it can be produced with the same type of material that constitutes the remaining part of the sealed package 1 and, therefore, the entire sealed package 1 can be recycled together without the need to separate the closing system 4 from the remaining part of the sealed package 1.

LIST OF REFERENCE NUMBERS OF THE FIGURES

-   -   1 sealed package     -   2 wrapping sheet     -   3 dispensing opening     -   4 closing system     -   5 semi-rigid plastic material sheet     -   6 pre-weakened region     -   7 outer incision     -   8 outer surface     -   9 inner incision     -   10 inner surface     -   11 supporting layer     -   12 heat-sealable layer     -   13 barrier layer     -   14 packing machine     -   15 reel     -   16 feeding duct     -   17 piercing device     -   18 application device     -   S1 unwinding station     -   S2 winding station     -   S3 longitudinal welding station     -   S4 transverse welding station 

1. A sealed break-open package (1); the sealed package (1) comprises: a wrapping sheet (2), which is folded and welded onto itself so as to define, alone, a closed containing chamber, which is designed to contain a fluid product and has a dispensing through opening (3), through which the fluid product can flow out of the containing chamber; and a closing system (4), which engages the dispensing opening (3) in a sealing manner, so as to close the dispensing opening (3); wherein the closing system (4) comprises a semi-rigid plastic material sheet (5), which overlaps the wrapping sheet (2) in the area of the dispensing opening (3), is firmly and permanently connected to the wrapping sheet (2), and has a pre-weakened region (6); and wherein the pre-weakened region (6) overlaps the dispensing opening (3) and guides, following a folding of the semi-rigid plastic material sheet (5), a controlled breaking of the semi-rigid plastic material sheet (5) in the area of the pre-weakened region (6), so as to determine the formation, through the semi-rigid plastic material sheet (5), of a product outlet opening.
 2. The sealed package (1) according to claim 1, wherein the pre-weakened region (6) is arranged at the centre of the dispensing opening (3), such that the pre-weakened region (6) coincides with a centre line of the dispensing opening (3).
 3. The sealed package (1) according to claim 1, wherein the pre-weakened region (6) comprises at least one outer incision (7), which is obtained through an outer surface (8) of the semi-rigid plastic material sheet (5), and at least one inner incision (9), which is parallel to and aligned with the outer incision (7) and is obtained through an inner surface (10) of the semi-rigid plastic material sheet (5), which is opposite the outer surface (8).
 4. The sealed package (1) according to claim 3, wherein the pre-weakened region (6) comprises a plurality of outer incisions (7) and a plurality of corresponding inner incisions (9).
 5. The sealed package (1) according to claim 3, wherein the semi-rigid plastic material sheet (5) is made up of a laminate comprising: a supporting layer (11) arranged on the outside, a heat-sealable layer (12) arranged on the inside, and a barrier layer (13) interposed between the supporting layer (11) and the heat-sealable layer (12).
 6. The sealed package (1) according to claim 5, wherein between the bottom of the outer incision (7) and the bottom of the inner incision (9) there is at least the barrier layer (13) and there is not the supporting layer (11).
 7. The sealed package (1) according to claim 6, wherein between the bottom of the outer incision (7) and the bottom of the inner incision (9) there is, besides the barrier layer (13), also the heat-sealable layer (12) and there is not the supporting layer (11).
 8. The sealed package (1) according to claim 5, wherein the supporting layer (11) has an interruption in the area of the bottom of the outer incision (7).
 9. The sealed package (1) according to claim 5, wherein: the outer incision (7) extends only in the supporting layer (11) of the semi-rigid plastic material sheet (5); and the inner incision (9) affects all three layers, i.e. the supporting layer (11), the heat-sealable layer (12) and the barrier layer (13), of the semi-rigid plastic material sheet (5).
 10. The sealed package (1) according to claim 5, wherein the barrier layer (13) of the semi-rigid plastic material sheet (5) is partially arranged inside the outer incision (7).
 11. The sealed package (1) according to claim 5, wherein there is a build-up of barrier layer (13) in the area of the bottom of the outer incision (7).
 12. The sealed package (1) according to claim 1, wherein the semi-rigid plastic material sheet (5) of the closing system (4) overlaps the inner surface of the wrapping sheet (2) and is located inside the containing chamber.
 13. The sealed package (1) according to claim 1, wherein: the dispensing opening (3) is arranged across one folding line of the wrapping sheet (2); and the pre-weakened region (6) is aligned with the folding line of the wrapping sheet (2).
 14. The sealed package (1) according to claim 1, wherein: the dispensing opening (3) is arranged across an edge of the containing chamber; and the pre-weakened region (6) is aligned with the edge of the containing chamber.
 15. The sealed package (1) according to claim 1, wherein: the pre-weakened region (6) extends along a straight line; and the dispensing opening (3) has a rectangular shape wherein the longer sides are parallel to the pre-weakened region (6) and the shorter sides are perpendicular to the pre-weakened region (6).
 16. (canceled) 